Abdominal exercise cycle



FIG. 1 is a front elevation view;

FIG. 2 is a rear elevation view;

FIG. 3 is a top plan view;

FIG. 4 is a bottom plan view;

FIG. 5 is a right side elevation view; and,

FIG. 6 is a left side elevation view. 

The ornamental design for a “abdominal exercise cycle,” as shown. 